Flask



I. R. CUSTER Aug. 8, 1933.

FLASK Filed Nov. 16. 1931 2 Sheets-Sheet l WNNNNNNNLNNR gwwe/wbo'c Ira R. Cu, 5 ier dual/mg Patented Aug. 8, 1933 uNrrEo STATES? 1,921,350 FLASK Ira R. Custer, El Paso, Tex.

Application November 16, 1931 r 9 Serial No. 575,394 1 9 Claims. (01. 22 97) I My inventionrelates to the. art of .casting and more particularly that branch of the art dealing with the casting ofdental restorations. The

technique for casting dental restorations for the 'sembledby suitable means whileth'e flask isbeing month, which are formed mostly out of gold, is as follows: Afterv making a model, one then makes a wax pattern of the difierentforms and designs tobe cast. The pattern is then invested wax is burnt out, thus leaving a cavity into which goldis 'forced'to fill the same,givingthe same;

design asthe wax formerly possessed. One frequently misses these castings after spending several hoursin their preparation because the mold is colder than the gold when itiis melted and forced into the same with the cast invested in acasting ring as is now the common practice. With the cast invested in a casting ring (flask) such as now is common practice, it is only practicable to heat the same to about 1500"F. for greater heat would melt the flask. By the time the flaskis removed from the fire,' placed in the casting machine (centrifuge) and the gold melted, the mold and flask will havecooled ofi about 700 F. As the gold used in dental prac-'' tice fuses between 1550 and-1600 F. before the v stituting the lower section, the parts being sepmolten gold can fill all crevices oithe moldcavity, it will have become chilled'and the cast is missed (spoiled). 1 a My invention, therefore, .ha'sfor an object to provide means to obviate these objectionable features and provides a flask byjthe'use or" which a denser mold is produced which, when set, may beremoved from the flask and heated to'a much *higher temperature than has heretofore been found practicable without cracking or-checking. In'this case the mold may be heated beyond the melting point of the geld used.

Further, my invention has ioran object to provide a flask of such construction that the mold may be freed easily and quickly, a flask embodiment shownin Figure 8.

in which the plastic material may be used mixed qiore thesqueezeis' appliedf" "as thick as possible and yet be workable, and in which the excess moisture may besqueezedout before the chemical action takes place in the plastic compound which causes it to set or be-' come hardened. 1 Another object of the telescopic-section flask whose sections are held extended by a removable member while the case is being embedded in the plastic investment be- 1 Generically, then; .my invention resides in the provision, ofa flask composedof telescoping sec-- tions having foraminous walls through which the invention is to provide a provide portions which telescope correspondingly water weeps-as the sections are squeezed together in a suitable flask press.

More-specifically the invention comprises a telescopic-section flask composed of walls held asused, but capable of being knocked down or taken apart for. the'purpose of freeing. the cast, the walls: having weep holes through which excess moisture is expelled while the flask is being telescoped in a suitable flask press. r

Other objects will in part be obvious and in part be pointed out hereinafter. V 7 To the attainment of the aforesaid objectsand ends,.the invention still further resides in the novel details of construction, combination and arrangement of. parts, all of which will be first fully described in the following detailed description, then be particularlypointed out in the appended claims, reference beinghad to the accompanying drawings, in Which:-- 1,

1 is a perspective view of the preferred top plate hav- Figure embodiment of the invention, the ing been removed.-

Figure 2 is a central vertical longitudinal section of the same withthetop plate in-place. 0

Figure 3 isa-perspective view of the parts conarated. r

the U-shaped braces" which it carries.

Figure 5is a detail cross section showing the manner of attaching the crucible forming core.

Figure dis a crosssection on the line6 "6 of Figure 2 en a slightly larger scale, showing the invention in use. I r p v j Figure 7 is a side elevation of the mold removed fromthe flask.

Figures is a perspective view ofanother embodiment of theinvention. Figure 9 is a vertical longitudinal section of the In the drawings, in which like numerals of reference indicate like parts in all of the figures, 1 represents the base which is provided with a groove 2 and is suitably'perforated as at 3 to provide weep holes. Set into the groove. 2 are end andside plates 4.- and 5 These plates have their meeting edges mitered as at 6 and they are se- 1 cured to thebasel by suitable screws 9 (preferably thumb screws or cap screws as indicated). The'side and end plates are stepped as at 7 to stepped portions of the'upper'section of the flask. The parts 1, 4. and'5 constitutethe-lowersection or" the flask. The end and side plates of the lower section of the flask are also perforated. at suitable intervals as at 8 to provide weep holes.

The upper section consists of end plates 10 and side plates 11, each having stepped portions 12 to telescope with the lower section, the lower edges of the plates 10 and 11 being bevelled as at 13 so that the upper section will easily find itself on the lower section. The plates 10 and 11 are also perforated as at I l to provide weep holes and their abutting edges are mitered as at 15.

Upper and lower U-shaped braces 16 and 1'? respectively are secured at 18 to the side plates of the upper section and extend overthe end plates of the upper section to which they are detachably secured by suitable cap or thumb screws 19.

In order to hold the upper and lower sections apart and prevent their telescoping while the,

pattern is being invested, I provide a U-shaped spring clip 20' which embraces the lower section above the step '7 and holds the upper section from telescoping. The member 20 has a handle 21 so that, it may be removed as soon as the flask has been put in the press preparatory to the application of the squeezing pressure.

22 designates a crucible forming core which is carried by one of the side plates of the upper section to which it is attached by suitable screws 23, the crucible forming core being perforated as at 24.

25 designates the mold which is provided with the crucible portion 26 and in which the wax pattern 27 is invested. 28 is a hole which is cut from the crucible 26 to the beginning of the wax pattern preparatory to the melting out of the wax andthe replacement thereof by the molten gold. 29 is a flange or shoulder formed on the mold 25 by reason of the bevel step 12 of the upper section of the mold.

.30 designates the apertured cover plate of the flask.

Instead of having the flask rectangular and made knocked down as shown in the first six figures of the drawings, a flask of circular form may ,beemployed. Whensuch a flask is made according to this embodiment of my invention, it consists of a lower section 31 and an upper section 32, the sections having telescoping portions 33 and acover 34, the cover and sections 32 and 31 being perforated at 35 to provide weep holes. V 7

.By the use of my invention, particularly the collapsible embodiment shown in Figures 1 to 8 inclusive,.I am enabled to mix my investment as thick as I can and still be workable. Having filled the flask with the thick composition and embedded the wax pattern therein, I remove the member 20 and apply a squeezingxpressure up and down in a suitable flask press, thus squeezing out the excess moisture through the weep holes from the flask. So in heating the mold it is not necessary to place the-flask in the oven with it as is now the case with ordinary casting rings.

From the foregoing description, taken in connection with the accompanying drawings, it is thought the comple e construction, operation and advantages of my invention will be clear to those skilled in the art.

What I claim is:

1. A flask comprising an upper and a lower section telescopically connected together and having foraminous walls.

2. A flask comprising telescopic sections each composed of separable walls, and means to hold the walls in assembled relation while the sections are being telescoped together, said walls being foraminous.

3. A flask having an upper and a lower section, said lower section comprising side and end walls and a base, means detachably securing the side and end walls to the base, the upper portion of the side and end walls beins stepped, the upper section or the flask comprising side and end walls, the lower portions of which are stepped to telescope the upper portions of the lower section, a cover plate over the walls of the upper section and means detachably holding the side and end walls of the up er section together.

4i. A. flask having an 1 sper and a lower section,

said low 1' section comprising side and end walls and a base, means detachably securing the side and end walls to the base, the upper portion of the side and end walls being stepped, the upper section of the flask comprising side and end walls, the lower portions of which are stepped to telescope the upper portions of the lower section, a cover plate over the walls of the upper section and detachably holding the side and end walls of the upper section together, said last named means comprising members carried by one pair of upper walls and embracing the other pair, and screws securing said members to said other pair of walls.

5. A flask comprising telescoping sections and a crucible-core securedin one of said sections, said sections core being composed of foraminous walls.

6. A flask having an upper and a lower section, said lower section comprising side and end walls and a base, detachably securing the side and end walls to the base, the upper portion of the side and end walls being stepped, the upper section of the flask comprising side and end walls, the lower portions of which are stepped to telescope the portions of the lower sections, a cover plate over the walls of the. upper section and means detachably holding the side and end walls of the upper section together, said means to secure the side and end walls to the base of the lower section comprisin a groove in the base into which said walls set, and screws passed through the base into said walls to hold them in the groove.

7. A flask having an upper and a lower section, said lower section comprising side and end walls and a means detachably securing the side and end v .lls to the base, the upper portion of the side and end walls being stepped, the

upper section of the flask comprising side and end walls, the lower portions of which are stepped to telescope the upper portions of the lower section, a cover plate over the walls or" theupper section and means detachably holding the side and end walls of the upper section together, and a ing for the purposes described.

9; A flask comprisingtelescopic sections each composed of-separable walls, means to hold the walls in assembled relation while the sections are being telescoped together, said walls being foraminous, and removable means for temporarily holding the sections against telescoping for the purposes described.

IRA R5 CUSTER; 

